scholarly journals Synthesis of Al3Fe5O12 Cubic Structure by Extremely Low Sintering Temperature of Sol Gel Technique

2009 ◽  
Vol 2 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Masoud
Keyword(s):  
Sintering Temperature ◽  
Sol Gel ◽  
Gel Technique ◽  
Cubic Structure ◽  
Low Sintering Temperature

Evolution of Phase Structure and Micro-Morphologies of the La0.7M0.3MnO3 (M=Ca, Sr) Sintered at Different Temperature

2015 ◽  
Vol 1095 ◽  
pp. 402-406
Author(s):  
Shao Qun Jiang ◽  
Gang Wang ◽  
Zong Shu Li ◽  
Ze Hua Wang ◽  
Ze Hua Zhou ◽  
...  
Keyword(s):  
Phase Structure ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Obvious Effect ◽  
Single Perovskite Phase ◽  
Solid State Sintering ◽  
Gel Technique ◽  
Cubic Structure ◽  
Sintering Method

The La0.7M0.3MnO3 (M=Ca, Sr) were synthesized by combining sol-gel technique and solid state sintering method. The evolutions of phase structure and micro-morphologies of the La0.7M0.3MnO3 with final sintering temperature (950-1250°C) were investigated. The results show that the La0.7Ca0.3MnO3 compounds exhibit single perovskite phase with cubic structure and the La0.7Sr0.3MnO3 compounds exhibit single perovskite phase with rhombohedra structure. The final sintering temperature has no obvious effect on the phase structure of La0.7Ca0.3MnO3. However, the density and grain size of La0.7M0.3MnO3 (M=Ca, Sr) increase with the increase of the final sintering temperature. Moreover, the micro-morphologies of La0.7Ca0.3MnO3 are more sensitive to final sintering temperature compared with that of La0.7Sr0.3MnO3. When sintering temperature is no less than 1150°C, the La0.7Ca0.3MnO3 has hardly any pore. After sintering at no less than 1250°C, the La0.7Sr0.3MnO3 becomes dense.

Study on the Properties of Al-Al2O3 Composite Using Synthesized Alumina from Sol Gel Technique

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Hasmaliza Mohamad ◽  
Hanisah Abdul Rani
Keyword(s):  
Metal Matrix ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Comparison Study ◽  
Commercial Alumina ◽  
Al2o3 Composite ◽  
Alumina Particles ◽  
Gel Technique ◽  
Ideal Method ◽  
The Ideal

Alumina reinforced aluminum is one of metal matrix composite (MMC) systems that can maintain its properties although at high temperature. Among various processes to produce MMC, powder metallurgy is the best method because of its efficiency dispersion of fine alumina particles. In this study, alumina powders were synthesized through sol gel method which is known as one of the ideal method to produce good properties of powders. The performances of synthesized alumina powders were then observed through the fabrication of composite. The percentage of alumina (0wt%, 10wt%, 20wt% and 30wt %) and sintering temperature (500°C and 550°C) were varied in order to observed their effects on the produced composite. Result shows that by increasing the percentage of alumina and sintering temperature, mechanical properties were increased where 30wt% alumina and 550°C sintering temperature give the optimum results. Comparison study by using 30wt% alumina and 550°C sintering temperature on the composite using synthesize and commercial alumina shows similar/comparable properties of composite.

scholarly journals Enhancement of Photocatalytic Activity by Mg2+ Doped Ceria Quantum Dots

2017 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Quantum Dot ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Cubic Structure

The pure and Mg2+ doped CeO2 quantum dot were synthesized by sol-gel technique. The prepared quantum dots were characterized using X-ray diffraction pattern (XRD), Scanning electron microscope (SEM-EDX). The XRD results show cubic structure of the CeO2 quantum dots. The crystalline size (D), microstrain (ε), dislocation density (δ) and lattice parameter (α) were calculated and analyzed. SEM-EDX analysis shows the morphology and the presence of elements. The photocatalytic activity of the synthesized quantum dot was evaluated based on the photodegradation of methylene blue (MB) by UV-Vis spectrometry.

scholarly journals Characteristics of unsupported alumina membrane prepared using sol-gel technique

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
M.R. Othman, ◽  
A.L. Ahmad ◽  
H. Mukhtar
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Alumina Membrane ◽  
Porous Support ◽  
Porosity Level ◽  
Gel Layer ◽  
Gel Technique ◽  
Coating Time

A laboratory scale alumina membrane was prepared using sol-gel technique. Results from the experiment demonstrate that the addition of PVA is important for viscosity adjustment to determine the appropriate coating time if the membrane is required for coating on the porous support. The effects of varying PVA content  and sintering temperature on the characteristics of the sintered membrane are discussed. In this work, a 2 volume % of PVA solution containing 4g of PVA in lOOml of water was discovered to be adequate to achieve appropriate porosity level and avoid cracks in the gel layer. It was also discovered that the sol viscosity essentially increased as the PVA addition was increased. On the contrary, the coating time decreased as PVA content in the sol was increased. Generally, the pore size of the membrane increased with the increase in PVA addition. The density of the membrane increased with increase in sintering temperature. The porosity level however, decreased as the temperature was increased. The pore size became greater and pore size distribution wider at higher sintering temperatures.

scholarly journals Effect of Zn Doping on Structural and some Optical Studies of Nano NiO Films Prepared by Sol-Gel Technique

2015 ◽  
Vol 53 ◽  
pp. 31-40 ◽  
Author(s):  
Foaad Sh. Hashim ◽  
Noor A. Sami
Keyword(s):  
Energy Gap ◽  
Sol Gel ◽  
Optical Transmittance ◽  
Optical Studies ◽  
Optical Energy Gap ◽  
Zn Doping ◽  
Grain Sizes ◽  
Gel Technique ◽  
Cubic Structure ◽  
Is Value

This research deals with the study of the structural andoptical properties of NiO and Zn doped NiO nano films with different ratios (0.01,0.05,0.1 mol %). NiO nano films in thickness 100nm were deposited on a glass substrate using sol-gel spin coating technique. XRD results indicated that the films are polycrystalline and have cubic structure with a preferred orientation along (111). The average grain sizes of the crystallites estimated from XRD data was found to lie in the range of 19.11 – 25.05 nm. Data of AFM indicate that the surface of films is smooth.The optical transmittance value of nano NiO film reaches to 94% in the VIS and NIR regions, while it is value of films deposited with 0.1mol%Zn reaches to (91)% which is important for its applications as window layers in solar cells. The values of optical energy gap of NiO and Zn doping by 0.01, 0.05 and 0.1 mol % were equal to 3.73, and 3.58,3.42, 3.41 eV respectively.

Porous Pellets of Tungsten Nano Powder: Investigation of Surface Porosity of Machined Surfaces

2018 ◽  
Vol 24 (8) ◽  
pp. 5527-5531
Author(s):  
K Shwetha ◽  
V Deepa ◽  
S. Prasanna Kumar ◽  
K. Santhosh Kumar ◽  
Meduri Ravi
Keyword(s):  
Sintering Temperature ◽  
Tungsten Powder ◽  
Sol Gel ◽  
Powder Particle Size ◽  
Surface Porosity ◽  
Porous Tungsten ◽  
Nano Powder ◽  
Dispenser Cathodes ◽  
Gel Technique ◽  
Tungsten Powders

The pressed dispenser cathodes are showing problem in machining due to their less strength because of low sintering temperature. In this paper, the synthesis of Nano tungsten powders and the fabrication of machinable porous Nano tungsten matrices were discussed. The Nano tungsten powders were synthesized by two different routes. One is by using Ammonium Meta Tungstate in sol gel technique and other is dissolving micron sized tungsten particles in Hydrogen Peroxide (H2O2). Using these synthesized Nano powders, the pellets were fabricated and the results were compared with the pellet made of commercially available tungsten powder (particle size 0.6–1 μ). The pressed porous tungsten buttons are sintered at high temperature and machining is carried out after copper infiltration. In this paper, surface morphology, hardness and machinability of porous tungsten Nano pellets were discussed.

Low-Temperature Sintering and Microwave Dielectric Properties of the Zn2SiO4 Ceramics

2009 ◽  
Vol 66 ◽  
pp. 104-107 ◽  
Author(s):  
Ying Dai ◽  
Yao Sun ◽  
Wen Chen
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Microwave Dielectric Properties ◽  
Low Temperature Sintering ◽  
Sintering Aid ◽  
Microwave Dielectric ◽  
Low Sintering Temperature

Willemite ceramics (Zn2SiO4) possess excellent millimeter-wave dielectric properties, but it also has a high sintering temperature above 1300°C by traditional solid-state reaction and relatively large negative τf value. Zn2SiO4 nanoparticles synthesized by Sol–Gel method were used to improve the sintering and dielectric properties of the Zn2SiO4 ceramics. Using the nanoparticles, Zn2SiO4 ceramics can be sintered at a low temperature, 1150°C and exhibited improved microwave dielectric properties of εr =6.62, Q × f=24500 GHz, τf =-59ppm/°C. By adding TiO2 with high positive τf value (+450 ppm/°C) and CuO as sintering aid, near zero τf value and low sintering temperature can be achieved. With 11wt% of TiO2 and 5 wt% of CuO, an εr value of 9.3, a Q × f value of 12200GHz and a τf value of -11 ppm/°C were obtained at 1000°C, confirming the promising potential of the CuO-added TiO2-Zn2SiO4 ceramics as candidate materials for low–temperature cofired ceramic (LTCC) devices.

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